ASTM  E1426  Determining the Effective Elastic Parameter for X-Ray

Scope

This ASTM E1426 test method outlines standard procedures for calculating the effective elastic parameter for residual and applied stress X-ray diffraction measurements. It also gives you a consistent way to report the precision of your measurements and the variables.

Procedure

In the ASTM E1426 test, the calibrated specimen is installed in the loading fixture and the fixture is placed in the X-ray diffraction machine. The specimen is stressed. While using the loading fixture, the specimen is loaded keeping an eye on the strain gauge readings. Stresses are applied in increasing sequence at levels, using a curve to translate strain gauge readings to apply stresses. The change is calculated in the interplanar distances at each stress level. The stresses are then applied in a decreasing order. If the deviations are more than the permissible level of uncertainty, residual stress measurements, and the source of the residual stress. So, before proceeding, deviations are identified and corrected for accurate results.

Specimen size

The width of the specimen used in the ASTM E1426 test should be sufficient to allow strain gauges, and the width-to-thickness ratio should be at least 1.

Data

The interplanar spacing and applied stress are calculated and further drawn on a graph for extracting results.

Conclusion:

This ASTM E1426 test method outlines standard procedures for calculating the effective elastic parameter for residual and applied stress X-ray diffraction measurements.